Other inventions are a combination of a base mounting plate with a vertical face perpendicular to the flow of snow and snow melt on the roof or a system of brackets that attached to either the roof surface with adhesives and/or fasteners or to the ribs of standing seam metal roof systems with rods that attach through or to those brackets creating a horizontal railing.
On those of the first type the uphill vertical edge of the base is usually perpendicular to the roof fall line and is therefore particularly susceptible to the effects of constant water flow and ice buildup making them susceptible to leakage or complete failure of the snow stop to remain attached to the roof. Even those that are diamond shaped (e.g., MOUNTAIN SNOW STOPS <http://www.snow stops.net/>) and thus can be mounted at an angle to the flow of water generally have bases that are large in area and cause the flow of snow melt water to have to flow around them after running into the snow stop. The greater the roof area above the snow stop the larger the amount of moisture impacting the base on which the vertical face that controls the snow from sliding is mounted.
Additionally the manufacture of the prior art is such that it typically requires multiple parts that require labor intensive steps to create a snow barricade railing or bulky molded pieces that are often fully formed prior to purchase and installation.
Thus, prior art snow stops are prone to mechanical failure due to snowmelt water pressure and are expensive.